Green’s Dictionary of Slang

(Aus.) to live as a vagrant; often as whale up the Lachlan v.

1898		Aus. Town & Country Jrnl (NSW) 15 Oct. 21/4: No true whaling kit is complete without [...] tea and sugar bag [...] dilly bag [...] and last - guess it - it's only for true whalers - a watrproof bag for the frogs (N.B. - Always carry a frogfor two for bait).
1905		‘Flash Jack from Gundagai’ in ‘Banjo’ Paterson Old Bush Songs 27: I’ve been whalin’ up the Lachlan, and I’ve dossed on Copper’s Creek.
a.1920		‘Flash Jack from Gundagai’ 🎵 I’ve been whalin’ up the Lachlan and I’ve dossed at Cooper’s Creek, / And once I rung Cudjingie shed and blued it in a week.
1957		J. Greenway ‘Australian Cattle Lingo’ in AS XXXIII:3 167: on the wallaby (track), to be, to whale up the lachlan, to hump a drum (bluey), v. phr. To wander with a swag, to hobo.